Method of cutting metals



V? Nov. 30, 1965 R. DIOGUARDI 3,220,149

METHOD OF CUTTING METALS Filed Nov. 1, 1963 3 Sheets-Sheet 1 Fig.1

INVENTOR Rena Dio guardi WeM MMZm LKW H/S ATTORNEYS Nov. 30, 1965 R. DIOGUARDI METHOD OF CUTTING METALS 5 Sheets-Sheet 2 Filed Nov. 1 1963 INVENTOR. Reno Dioguard/ BY WM, MJ BMM HIS ATTORNEYS f Nov. 30, 1965 R. DIOGUARDI METHOD OF CUTTING METALS 3 Sheets-Sheet 5 Filed Nov. 1, 1965 1NVENTOR. Reno Dioguard/ BY M017,

HIS A TTORNE Y3 United States Patent 0 3,220,149 METHUD 0F CUTTING METALS Reno Dioguardi, 497 Delaware Ave, Rochester, Pa. Filed Nov. 1, 1963, Ser. No. 323,189 20 Claims. (Cl. 51281) This application is a continuation-in-part of my application Serial No. 109,334 filed May 11, 1961, now abandoned, and relating to Method of Cutting Metals.

My invention relates to a method for cutting metals and particularly metals which are difiicult to sever such as titanium, titanium based alloys, zirconium and alloys there-of, certain steels including austenitic stainless types, Hadfield manganese, refractory alloys, cermets, etc. This method finds special utility in cutting large, thick sections of steel which previously were severed by abrasive disk saws or by flame-cutting. In addition to cutting titanium based alloys and alloy steels, my method is also useful for cutting cast iron, brass, bronze, copper, aluminum and other nonferrous metals and alloys.

Heretofore, the steel industry has experienced substantial costs in cutting steel which have ranged from about 15% to about 40% of the cost of the steel manufactured and sold. A number of difierent methods have been employed including hack sawing, circular cold sawing, band sawing, abrasive disk sawing, shearing, machine parting, and flame-cutting. Except for flame-cutting, each of the other methods has limitations regarding thickness of steel which can be cut and, accordingly, the steel industry has lacked a method for cutting large, thick sections which are free from serious deficiencies resulting from flamecutting.

While flame-cutting has applicability to almost any length and thickness of steel, it has serious and important drawbacks and shortcomings. In the first place, flamecutting of a number of different steels necessarily includes special techniques and additional practices such as preheating, postheating, stress relief anneals, etc. Although carbon steel up to about 0.35% carbon can be cut without difficulty, heavy sections such as plates 4 thick and thicker preferably receive a stress relief anneal to avoid cracking due to contraction if cooled too rapidly. Carbon steels above 0.35% carbon are preheated to about 600 F. to prevent hardening and cracking.

Steels having up to 14% manganese and 1.5% carbon are difficult to flame-cut and generally require preheating.

To obtain good mechanical properties in silicon steels containing considerable amounts of carbon and manganese, careful preheating and postannealing are essential.

Tungsten steel alloys where tungsten exceeds about 14% are diflicult to flame-cut and steel alloys of the air hardening type should be preheated and postheated when flame-cut.

Stainless steels are almost impossible to cut by conventional oxygen-cutting practices because chromium oxide is formed and prevents continuation of cutting. Accordingly, flame-cutting of such steels requires either a chemical flux or iron powder to flux the chromium oxide. However, even when using a chemical flux or iron powder, unstabilized grades of stainless steel encounter carbide precipitation in a zone about /s to A thick from the cut. These zones are usually removed by grinding or machining.

Both high molybdenum-tungsten steels and cast iron containing up to 4% carbon require special flame-cutting techniques.

In the second place, flame-cutting produces a scalloped or ragged kerf whose size is dependent upon thickness of cut and operators skill. As the thickness of cut increases, the amount of kerf also increases and, in many 3,Z20,l4 9 Patented Nov. 30, 1965 instances, the kerf must be removed by grinding or machining operations which not only add to the cost of fabrication but also produce excessive metal loss.

In the third place, flame-cutting thicknesses over about 18" encounter difficulty from an accuracy of cut standpoint.

In the fourth place, flame-cutting is expensive amounting to about 41 per lineal foot.

Shearing steel has a thickness limitation of about 2 but in the case of some alloys such as high strength, low allow steels, the limitation is about 1" and for Hadfield manganese steels, about Hack sawing is restricted to thicknesses and lengths defined by height of the saw frame and length of the blade and of the stroke, respectively. An additional restriction is the hardness of the steel to be cut by hack sawing, generally limited to hardness under 300 Brinell. In the case of some stainless types of steel, hack sawing finds little use because the teeth of the blades do not stand up in service and dull quickly.

Circular cold sawing has application to heavy steel sections such as blooms and billets with a maximum thickness of cut of about 20". The diameter of the blade limits the thickness of cut and this type of sawing is not used on stainless steels and on steels having a hardness of over about 300 Brinell because the teeth of the saw dull too quickly when used on those steels.

Band sawing is normally confined to thin sheet and strip steel not over about /2 thick and friction sawing to thicknesses up to about 3 to 4". If thicker steel is cut, the saw blades become fouled and a personnel safety problem arises. Stainless steel is not cut by either band or friction sawing.

The thickness of metal cut by abrasive disk sawing is usually limited by the diameter of the blade and generally does not exceed 4 to 5". As cutting with an abrasive disk blade progresses, its diameter becomes smaller due to continuous wearing away thereof. Accordingly, the amount of thickness which an abrasive disk blade can cut is continuously reduced while in service.

I have invented a method of cutting metals which has practically no thickness limitations, which produces almost a machine finish on the surface cut, and which avoids the shortcomings of the cutting practices described herein. Specifically, my invention comprises moving a length of wire across and in engagement with a piece of metal to be cut so that a part of the length of the wire engages the piece of metal along substantially the length of cut. The moving is such that in travel across and in engagement with the piece of metal, the part of the length of wire travels in a path substantially parallel to the longitudinal axis of the part of the length to produce a out which extends substantially in the direction of moving. A mixture of individual and free abrasive particles and a liquid is delivered to the piece of metal and to the wire at that portion of the piece where the wire first engages same in its movement to and across the piece. Also, the mixture is delivered to the piece along at least a portion of the cut and a portion of the metal where the wire engages the metal. This delivery of the mixture is carried out substantially throughout advancing the wire into and through the metal. During the moving, the wire is advanced into and through the piece of metal as the cutting thereof progresses. The cutting is performed with a tension in the Wire of an order of magnitude of at least about 25,000 p.s.i. in a /2 inch diameter wire.

To cut shapes in the metal section during the moving of the wire, it is guided and advanced into and through the piece of metal as cutting progresses with the guiding being along a route corresponding to the shape to be cut.

Some of the abrasive particles which are satisfactory for carrying out my method include corundum or aluminum oxide; silica sand; carbides of silicon, boron, tungsten and. titanium; and diamond grains. It is important that the abrasive particles be free and independent of one another so that the wire in its travel across and in engagement with the metal imparts movement or motion to the particles relative to the metal and brings the particles into engagement with that part of the metal to be cut, thereby effecting severing thereof.

Water is a satisfactory liquid for mixture with abrasive particles; and other liquids such as oil, and especially kerosene, are also suitable. It is important that the liquid selected not chemically react with or stain the metal.

The liquid not only functions as a carrier for the abrasive particles but also assists in keeping the wire and that part of the metal engaged by the wire cooled throughout cutting. In most instances, cutting is effected with little or no heating of the wire or metal adjacent to the cut even when completely severing long and heavy sections 12" to 96" thick. Accordingly, severing of heat-sensitive steels by the method avoids preheating and/or postheating, thus lowering materially costs of cutting and in the case of flame-cutting, reducing metal loss.

The mixtures of the individual and free abrasive particles and liquids used in practicing my method have a fairly wide range of proportions of abrasive particles to liquid. An abrasive consumption of about 1 to 2 pounds per superficial foot of cutting and a water consumption of about 2 gallons per minute have produced satisfactory results.

I have found that aluminum oxide is a good abrasive for cutting steels, alloy steels, refractory alloys and cermets and that silicon carbide is a good abrasive for cutting zirconium, titanium and alloys thereof.

For efficient cutting, the mixture of liquid and the free abrasive particles is about 60-80% abrasive particles and preferably about 70-80% abrasive particles by volume. Where the abrasive particles amount to 20-50% by volume, unsatisfactory cutting results are obtained from the standpoint of rate of cutting, life of the cutting wire and ability to control the direction of cut.

Generally, linear rate of travel of the wire is from about 3,600 to about 4,500 feet per minute. However, the rate of travel can be less than 3,600 feet perminute or more than 4,500 feet per minute and effect acceptable results.

The amount of tension which I impart to the wire during cutting is important and must have an order of magnitude of at least about 25,000 p.s.i. as determined in a /2 inch diameter wire. I have found that tensions of about 30,000 to about 55,000 p.s.i. produce good results; but when lighter tensions are used, the rate of cutting is either too low or one achieves almost no cutting and in some instances, merely abrades the wire.

In wire sawing in the stone industry, light tensions are used in the order of 3,000-7,500 p.s.i. to effect good cutting results. However, when higher tensions are used in stone cutting, difiiculty in control over the direction of cut is experienced so that the stone industry avoids high tensions and certainly tensions about 25,000 p.s.i. and greater.

I have found that the tension can be imparted to the wire in various ways, including forcing apart the wheels or pulleys around which the wire travels to generate the desired amount of tension in the wire for cutting the metal. Such tension is maintained substantially throughout cutting for the reasons already mentioned. Another way of imparting tension to the wire comprises lowering the carriage or frame which mounts the wheels or pulleys around which the wire travels an amount which produces an upward bow in the wire as shown in FIGURE 1 which is described more in detail hereinafter. This carriage or frame is so lowered that the wire is tensioned in its engagement with the metal piece and this tension is maintained substantially throughout the cutting operation by a regulated lowering of the carriage to maintain the upward bow in the wire.

In the accompanying drawings I have shown difierent machines on which my method can be successfully practiced, in which:

FIGURE 1 is a side elevation view of one type of machine on which metal is cut according to my method;

FIGURE 2 is a side elevation view of a second type of machine on which metal is cut according to my method;

FIGURE 3 is a side elevation view of a machine on which desired shapes of metal are out according to my method;

FIGURE 4 is a plan view of a device of the machine of FIGURE 3 which permits cutting a desired shape from a metal section;

FIGURES 5 and 6 show two types of wire which are used in practicing my method; and

FIGURE 7 is a side elevation view of a third type of wire saw machine on which my method is practiced.

Referring to the drawings, FIGURE 1 shows a wire saw machine comprising a pair of spaced apart vertical posts 1 mounting therebetween a horizontal frame 2 which travels vertically up and down on the posts. The frame carries at one end a winding reel 3 and at the other end an unwinding reel 4 together with a reversible motor (not shown) drivingly connected to each reel. Extending between each reel and wound thereon is a length of wire 5 which travels in the direction of arrows 6 across and in engagement with a thick, heavy section of steel 7 disposed upon base 8 beneath the platform 2. Winding reel 3 coils the wire thereon while unwinding reel 4 uncoils it. Each reel is reversible so that when most of the wire has been unwound from reel 4 and wound upon reel 3, the direction of rotation of the reels is reversed and reel 3 becomes the unwind reel and reel 4 the winding reel with the wire traveling in a direction opposite to that of the arrows 6. Thus, during cutting of the steel section, the travel of the wire is reversed periodically after most of it has been uncoiled from the unwind reel and coiled upon the winding reel.

A guide roller 9 mounted upon each end of the platform 2 by an arm 10 rides the upper side of the wire 5 as it travels across the steel section 7 and places a light tension thereon to assist cutting.

A mixture of free and independent abrasive particles and water is delivered to the section by a funnel and conduit combination 11 positioned for directing the mixture onto that part of the section where the wire first engages the metal. It is important that the mixture be delivered to the wire where it first contacts the metal to start the cutting for otherwise there would be little or no cutting since the wire without the mixture does not effect cutting of the metal. To assure a supply of the mixture where the wire first engages the metal, a box 8a for receiving and holding the mixture is disposed on the entry sides of the metal section. Since the direction of wire travel is reversible, there is a box on each side of the metal section. When travel of the wire is reversed, then delivery of the mixture is transferred from the combination 11 to a second one 12 disposed at the opposite end of the steel section 7. Delivery of the mixture is guided into the groove formed by the wire and is continued substantially through out cutting to enhance and expedite it.

The horizontal platform is continuously lowered during cutting to advance the wire through the section as cutting progresses by operation of screw shafts 13 which are in engagement therewith. Usually, the platform is lowered so that the wire applies a light downward pressure of about 25 pounds on the steel section.

FIGURE 2 shows a second type of machine which severs metal by travel of an endless wire 14 across and through a section 15 of steel in a direction shown by arrow 15a. The machine of FIGURE 2 is similar to that of FIGURE 1 except that a single motor 16 provides the driving power for travel of the endless wire around motor driven reel 17 and idler reel 18. A horizontal platform 19 mounts the two reels and is lowered as cutting of the steel progresses so that the wire is maintained in engagement with the steel section in the same manner as the wire 5 of the machine of FIGURE 1.

As shown in FIGURE 2, a recycling system 20 for the mixture of abrasive particles and water provides recovery and collection of the mixture below the section 15 by a tank 21. A pump 22 conveys the collected mixture from the tank 21 to a funnel and conduit combination 23 which delivers it to the steel section during cutting including a box 23a on the entry side of the section 15 so that there is mixture at that place where the wire first engages the metal.

Since the endless wire travels in a single direction as shown by the arrow 15a, a single funnel and conduit combination suffice for delivery of the mixture upon that end of the section of steel where the wire first engages it.

Preferably, the wire is made from an abrasion resistant steel such as one having an analysis of about 0.350.50% carbon, 1 /z2% manganese, or a Hadfield manganese steel to provide long service life. As shown in FIGURE 5, the wire is made from two strands 24 and 25 twisted together to form longitudinally, helically running grooves 26 which assist in carrying the free abrasive particles along the direction of wire travel and from that end of the section where the mixture is delivered to the other end.

The combination of travel of the wire and of the grooves assist cutting along substantially the length of cut defined by that part of the length of the wire in engagement with the steel. This travel of the wire works, moves and forces the abrasive particles down into the steel and imparts motion or movement thereto to achieve severance of the steel.

FIGURE 6 shows a plurality of pockets or cavities 27 spaced along the length of the wire to carry the abrasive particles from one end to the other of the steel section and thereby performs the same function as the grooves 26 in the wire of FIGURE 5. While the wire may have the grooves 26 or pockets 27 or some other similar means for assisting in conveying the abrasive particles lengthwise of the cut, around, smooth wire without any groove or pocket satisfactorily acts upon the particles to etfect cutting when operated in the same manner as the wires of FIGURES 1 and 2 and of FIGURES 3, 4, 7 and 8 (to be described hereinafter).

While the wires shown in FIGURES 5 and 6 are round in cross section, I can also use wire which in cross section is triangular, square, rectangular, etc.

The machine of FIGURES 3 and 4 permits cutting shapes in a steel section 28 by guiding an endless wire 29 during its travel therethrough. As shown, the wire is endless and travels over a motor driven reel 30 and idler reels 31 and 32 during cutting of the steel section 28. The reels are mounted upon a swingable frame 33 which, in turn, is joined to a main frame 34 mounted for travel in a horizontal plane about vertical pivots 35 and 36. The wire is vertically positioned relative to the section of steel and the mixture of abrasive particles and 'water is delivered from a conduit 37 to a funnel 38 located just above the steel section.

To cut a given shape, a tracer roller 39 engages and travels the periphery 40 of a pattern 41 whose shape is that to be cut from the section 28. The path of travel of the tracer roller as it rides the pattern is transmitted by a pantograph 42 in combination with a parallelogram 43 to the frames 33 and 34 to guide the wire through the section 28 as cutting progresses. A handle 44 connected to a sleeve 45 depending from arm 46 of the frame 33 and through which the wire 29 travels provides a means for manual feeding or advancing the wire through the section 28 along the path defined by the pattern 41.

FIGURE 7 shows an oscillating type of machine on which steel sections are severed according to my method. The machine comprises a length of wire 47 extending between and attached to the ends of two spaced apart pivoted arms 48 and 49 mounted upon a horizontal frame 50 disposed for vertical up and down travel on upright posts 51 and 52 and connected by horizontal arm 50a. An oscillating motor 53 connected to the upper end of arm 49 through a link 54 imparts oscillating horizontal movement to the wire 47 which is held under light tension by guide rollers 55 and 56. Threaded shafts 57 and 58 move the horizontal frame vertically on the posts as cutting progresses to maintain the wire in engagement with a steel section 59. Delivery of the mixture of abrasive particles and water is along the length of cut as shown from a hopper 6t) and conduits 61.

The mixture of abrasive particles and water is delivered to the section by the hopper 60 and the con duits 61 along the length of cut as shown in FIGURE 7 as well as that place where the wire first engages the metal as shown in FIGURES 1 and 2.

I have carried out a number of cutting operations as evidenced by five examples (to be described herein) on a machine of the type shown in FIGURE 2. In cutting these examples, the mixture was water and 60/ silicon carbide particles with water consumption about 2 gallons per minute and silicon carbide consumption about 1 to 2 pounds per superficial foot of cut. The lineal speed of travel of the wire was about 4,000 feet per minute. The examples are as follows:

Example 1 A 2" thick cross section piece was cut from a cast iron bar 2%" wide, 2%" thick, and 18" long in 21 minutes.

Example 2 A bar of titanium 2%" thick, 2" wide, and 11" long was cut longitudinally therethrough in about 1 hour 15 minutes. The analysis of the titanium was 13% vanadium, 11% chromium, 3% aluminum, and the ba ance titanium.

Example .5

A bar of austenitic stainless steel 4% wide, 7 thick, 8%" long was severed longitudinal in 14 minutes. The analysis of the austenitic stainless steel was 0.08% carbon, 25% nickel, 18% chromium, 1%% molybdenum, 1 /2% copper, and /2% titanium.

Example 4 A bar of stainless steel 5%" wide, thick, and 7 /8" long was cut longitudinally therethrough in about 20 minutes. The analysis of this stainless steel was 0.08% carbon, 17% chromium, 7% nickel, 1 /2% titanium, and 0. 5% aluminum.

Example 5 case with flame-cutting where large, uneven and sealloped shaped kerfs result.

In the third place, almost any metal can be cut without preheating, post'heating, and/ or stress relief annealing because severing is accomplished without heating the metal during cutting.

In the fourth place, except for flame-cutting which has many substantial drawbacks, the method permits cutting of shapes from thick, heavy sections.

In the fifth place, cost of cutting by my method is low and its speed is superior to many of the cutting methods now employed in the steel industry.

While I have shown and described preferred embodiments of my invention, it is to be understood that it may be otherwise embodied within the-scope of the following claims.

I claim:

1. A method of cutting metal comprising moving a length of wire across and in engagement with a piece of metal to be cut so that a part of said length engages said piece of metal along substantially the length of cut, said moving being such that in travel across and in engagement with said piece of metal said part of said length of wire travels in a path substantially parallel to the longitudinal axis of said part of said length to produce a cut extending substantially in the direction of said moving, delivering a mixture of individual and free abrasive particles and a liquid to said .piece of metal and to said wire at that portion of said piece where said wire first engages same in its movement to and across said piece and to said piece of metal along at least a portion thereof where said wire engages said metal, during said moving advancing said wire into and through said piece of metal as the cutting thereof progresses, carrying out said delivery of said mixture substantially throughout said advancing of said wire into and through said metal, and performing said cutting with a tension in said wire of an order of magnitude of at least about 25,000 p.s.i. in a /2" diameter wire.

2. The method of claim 1 characterized by carrying out said cutting with a tension of at least about 25,000 p.s.i. in said wire.

3. The method of claim 1 characterized by said mixture being about 60-80% abrasive grains by volume.

4. The method of claim 1 characterized by said metal being one of steel, alloy steel, refractory alloy and a cermet, and by said abrasive particles being aluminum oxide.

5. The method of claim 3 characterized by said aluminum oxide being about 60-80% by volume of said mixture.

6. The method of claim 1 characterized by said metal being one of zirconium, titanium and alloys thereof, and by said abrasive grains being silicon carbide in an amount of about 60-80% by volume of said mixture.

7. The method of claim 1 characterized by said moving comprising oscillating said length of wire.

8. The method of claim 1 characterized by said moving comprising substantially regular intermittent engagement of said wire with said metal.

9. A method of cutting metal comprising moving an endless wire across and in engagement with a piece of metal to be cut so that a part of the length of said endless Wire engages said piece of metal along substantially the length of cut, said moving being such that in traveling across and in engagement with said piece of metal said part of said length of endless wire travels in a path substantially parallel to the longitudinal axis of said part of said length to produce a cut extending substantially in the direction of said moving, delivering a mixture of individual and free abrasive particles and a liquid to said piece of metal and to said wire at that portion of said piece where said wire first engages same in its movement to and across said piece and to said piece of metal along at least a portion thereof where said wire engages said metal, during said moving advancing said wire into and through said piece of metal as the cutting thereof progresses, carrying out said delivery of said mixture substantially throughout said advancing of said wire into and through said metal and performing said cutting with a tension in said wire of an order of magnitude of at least about 25,000 p.s.i. in a /2" diameter wire.

10. The method of claim 9 characterized by carrying out said cutting with a tension of at least about 25,000 p.s.i. in said wire.

11. The method of claim 9 characterized by said mixture being about 60-80% abrasive grains by volume.

12. The method of claim 9 characterized by said metal being one of steel, alloy steel, refractory alloy and a cermet, and by said abrasive particles being aluminum oxide.

13. The method of claim 12 characterized by said aluminum oxide being about 60-80% by volume of said mixture.

14. The method of claim 9 characterized by said metal being one of zirconium, titanium and alloys thereof, and by said abrasive grains being silicon carbide in an amount of about 60-80% by volume of said mixture.

15. A method of cutting a given shape of metal from a piece of metal comprising moving a length of wire across and in engagement with said piece of metal to be cut so that a part of said length of wire engages said piece of metal along substantially the length of out, said moving being such that in travel of said length of wire across and in engagement with said piece of metal said part of said length of wire travels in a path substantially parallel to the longitudinal axis of said part of said length to produce a cut extending substantially in the direction of said moving, delivering a mixture of individual and free abrasive particles and a liquid to said piece of metal and to said wire at that portion of said piece where said wire first engages same in its movement to and across said piece and to said piece of metal along at least a portion thereof where said wire engages said metal, during said moving guiding and advancing said wire into and through said piece of metal as cutting thereof progresses, said guiding being along a route which corresponds to said shape to be cut, carrying out said delivery of said mixture substantially throughout said advancing of-said wire into and through said metal, and performing said cutting with a tension in said wire of an order of magnitude of at least about 25,000 p.s.i. in a A2" diameter wire.

16. The method of claim 15 characterized by carrying out said cutting with a tension of at least about 25,000 p.s.i. in said wire.

17. The method of claim 15 characterized by said mixture being about 60-80% abrasive grains by volume.

18. The method of claim 15 characterized by said metal being one of steel, alloy steel, refractory alloy and a cermet, and by said abrasive particles being aluminum oxide.

19. The method of claim 18 characterized by said aluminum oxide being about 60-80% by volume of said mixture.

20. The method of claim 15 characterized by said metal being one of zirconium, titanium and alloys thereof, and by said abrasive grains being silicon carbide in an amount of about 60-80% by volume of said mixture.

References Cited by the Examiner UNITED STATES PATENTS 589,199 8/1897 Wincgz et al. 1,306,636 6/1919 Selby -12 X 2,129,969 9/1938 Showalter 51-62 X 2,792,825 5/1957 Letter 125-21 2,793,478 5/1957 Rohowetz 51407 2,866,448 12/1958 Dessureau et al 125-21 LESTER M. SWINGLE, Primary Examiner. 

1. A METHOD OF CUTTING METAL COMPRISING MOVING A LENGTH OF WIRE ACROSS AND IN ENGAGEMENT WITH A PIECE OF METAL TO BE CUT SO THAT A PART OF SAID LENGTH ENGAGES SAID PIECE OF METAL ALONG SUBSTANTIALLY THE LENGTH OF CUT, SAID MOVING BEING SUCH THAT IN TRAVEL ACROSS AND IN ENGAGEMENT WITH SAID PIECE OF METAL SAID PART OF SAID LENGTH OF WIRE TRAVELS IN A PATH SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID PART OF SAID LENGTH TO PRODUCE A CUT EXTENDING SUBSTANTIALLY IN THE DIRECTION OF SAID MOVING, DELIVERING A MIXTURE OF INDIVIDUAL AND FREE ABRASIVE PARTICLES AND A LIQUID TO SAID PIECE OF METAL AND TO SAID WIRE AT THAT PORTION OF SAID PIECE WHERE SAID WIRE FIRST ENGAGES SAME IN ITS MOVEMENT TO AND ACROSS SAID PIECE AND TO SAID PIECE OF METAL ALONG AT LEAST A PORTION THEREOF WHERE SAID WIRE ENGAGES SAID METAL, DURING SAID MOVING ADVANCING SAID WIRE INTO AND THROUGH SAID PIECE OF METAL AS THE CUTTING THEREOF PROGRESSES, CARRYING OUT SAID DELIVERY OF SAID MIXTURE SUBSTANTIALLY THROUGHOUT SAID ADVANCING OF SAID WIRE INTO AND THROUGH SAID METAL, AND PERFORMING SAID CUTTING WITH A TENSION IN SAID WIRE OF AN ORDER OF MAGNITUDE OF AT LEAST ABOUT 25,000 P.S.I. IN A 1/2" DIAMETER WIRE. 